This invention relates to accessories for machine tools, and more particularly to clamp collars and shaft couplings.
It is well known in the art to provide clamp collars, shaft couplings and the like (hereinafter generally referred to as collars or clamp collars) which may be removably mounted on a rotating shaft, for example, of a rotating machine. Typical clamp collars are generally C-shaped and include a flexure portion between the end portions thereof. A screw coupling for the two end portions is adapted for drawing the end portions towards each other and securing the collar at its inner surface to the shaft.
The conventional clamp collars, however, are typically selected for use on a shaft of a radius R, where the collar has a slightly larger "radius" r.sub.1. After the collar is slid onto the shaft, the screw which couples the two end portions of the collar is tightened to draw the collar about the shaft. The tightened collar is thereby deformed slightly in order to clamp the collar to the shaft. The amount of clamping is dependent upon the force applied by the screw. The screw is first torqued in order to draw the clamp to the shaft, and then is torqued in order to tighten the drawn-to collar tight around the shaft in a clamping fashion. Thus, only the secondary torquing is used to clamp the collar to the shaft. The energy to establish the initial torquing, by which the collar is drawn to the shaft, has little or no effect on the clamping capability of the collar, and thus represents an unnecessary expenditure of energy.
It is therefore an object of the present invention to provide a new and improved clamp collar.